Effect of radioactive cesium-rich microparticles on radioactive cesium concentration and distribution coefficient in rivers flowing through the watersheds with different contaminated condition in Fukushima

Takahiro Tatsuno; Hiromichi Waki; Minato Kakuma; Naoto Nihei; Tsugiko Takase; Toshihiro Wada; Kazuya Yoshimura; Takahiro Nakanishi; Nobuhito Ohte

doi:10.1016/j.jenvman.2022.116983

Effect of radioactive cesium-rich microparticles on radioactive cesium concentration and distribution coefficient in rivers flowing through the watersheds with different contaminated condition in Fukushima

J Environ Manage. 2023 Mar 1:329:116983. doi: 10.1016/j.jenvman.2022.116983. Epub 2022 Dec 22.

Authors

Takahiro Tatsuno¹, Hiromichi Waki², Minato Kakuma³, Naoto Nihei⁴, Tsugiko Takase⁵, Toshihiro Wada⁶, Kazuya Yoshimura⁷, Takahiro Nakanishi⁸, Nobuhito Ohte⁹

Affiliations

¹ Institute of Environment Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan. Electronic address: t.tatsuno@ier.fukushima-u.ac.jp.
² Graduate School of Informatics, Kyoto University, Yoshida Hommachi, Sakyo-ku, Kyoto, 606-8501, Japan. Electronic address: waki.hiromichi.54s@st.kyoto-u.ac.jp.
³ Graduate School of Informatics, Kyoto University, Yoshida Hommachi, Sakyo-ku, Kyoto, 606-8501, Japan. Electronic address: kakuma.minato.36r@st.kyoto-u.ac.jp.
⁴ Faculty of Food and Agricultural Science, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan. Electronic address: nihei@agri.fukushima-u.ac.jp.
⁵ Graduate School of Symbiotic Systems Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima, 960-1248, Japan. Electronic address: ttakase@sss.fukushima-u.ac.jp.
⁶ Institute of Environment Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan. Electronic address: t-wada@ipc.fukushima-u.ac.jp.
⁷ Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 45-169 Sukakeba, Kaibama, Haramachi-ku, Minamisoma City, Fukushima, 975-0036, Japan. Electronic address: yoshimura.kazuya@jaea.go.jp.
⁸ Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 45-169 Sukakeba, Kaibama, Haramachi-ku, Minamisoma City, Fukushima, 975-0036, Japan; Nuclear Science Research Institute, Japan Atomic Energy Agency, 2-4 Shirakata,Tokai-mura,Naka-gun, Ibaraki, 319-1195, Japan. Electronic address: nakanishi.takahiro@jaea.go.jp.
⁹ Graduate School of Informatics, Kyoto University, Yoshida Hommachi, Sakyo-ku, Kyoto, 606-8501, Japan. Electronic address: nobu@i.kyoto-u.ac.jp.

PMID: 36565500
DOI: 10.1016/j.jenvman.2022.116983

Abstract

Radioactive cesium-rich microparticles (CsMPs) derived from the Fukushima Daiichi Nnuclear Power Plant accident were detected from soils and river water around Fukushima Prefecture, Japan. Because CsMPs are insoluble and rich in radioactive cesium (RCs), they may cause the overestimation of solid-water distribution coefficient (K_d) for RCs in the water. Previous studies showed the proportion of RCs derived from CsMPs on RCs concentration in soils collected from areas with different contaminated levels. Because the proportion of RCs concentration derived CsMPs to the RCs concentration of soils in the less contaminated areas is higher than that in the highly contaminated areas, the effect of CsMPs on particulate RCs concentration in river water may be larger in the less contaminated areas. However, the difference in the effects of CsMPs on the particulate RCs concentration and K_d in river water flowing through watersheds with different contaminated levels has not been clarified. In this study, we investigated the effect of CsMPs on the particulate RCs concentration and K_d in two rivers, Takase River and Kami-Oguni River, flowing through the watersheds with different RCs contaminated levels in Fukushima Prefecture. CsMPs might enter rivers due to soil erosion because they were detected only in some samples collected from both rivers during flood events. CsMPs accounted for more than half of particulate RCs concentration in some water samples collected in the flood condition. In particular, the proportion of CsMPs in particulate RCs for the Kami-Oguni River was greater than that for the Takase River. However, when evaluating for the entire water sampling in the flood condition, a proportion of RCs concentration derived from CsMPs in the average RCs concentrations per unit mass of SS in both river waters collected in the flood condition was not large. CsMPs might temporarily increase the particulate RCs concentration and K_d in the flood event, but CsMPs did not significantly affect them when evaluated throughout the event.

Keywords: Fukushima; Radioactive cesium; Radioactive cesium-rich microparticles; Soil erosion; Water sampling.

MeSH terms

Cesium
Cesium Radioisotopes / analysis
Dust
Fukushima Nuclear Accident*
Japan
Nuclear Power Plants
Radiation Monitoring*
Rivers
Soil
Water
Water Pollutants, Radioactive* / analysis

Substances

Cesium Radioisotopes
Water Pollutants, Radioactive
Cesium
Water
Dust
Soil